A man and a woman have been arrested by police after a mother was stabbed while walking with her young child.
Abigail Witchalls teaches English to immigrant women
Abigail Witchalls, 26, is critically ill in hospital after being stabbed in the neck in Little Bookham, Surrey, on Wednesday afternoon.
She was attacked as she pushed her 21-month-old son Joseph in a buggy.
On Friday, Surrey Police said the man, 28, and woman, 29, had attended a police station voluntarily. A blue Peugeot car was also seized by police.
Det Supt Adrian Harper said officers were trying to confirm whether the car was the same one seen speeding close to where Mrs Witchalls was stabbed.
He said the arrests were "obviously a significant development", but only one line of inquiry.
The man and woman were arrested after walking into Leatherhead police station and are being held elsewhere in the county.
Mrs Witchalls is being treated at the St George's Hospital, in south London, where relatives are keeping a bedside vigil.
Det Supt Harper said she was so seriously injured that she was given the last rites after the attack.
She was attacked on a private lane off Burnhams Road, in Little Bookham.
Police said there was no sign of a struggle, and nothing had been removed from the rucksack she had been carrying.
Mrs Witchalls' son Joseph was found out of his buggy and beside his mother on the ground after the stabbing.
He was shocked, but unhurt, and is being cared for by family.